Abrading machine



Aug. 5, 1930. w. PRATT ABRADING MACHINE Filed Sept. 2a, 192:

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Patented Aug- 5, 1930 7 UN ST wIL IAMrRATr, or Bnrs'ron, CONNECTICUT, ASSIGNOR T THE'NEW DEPARTURE MANUFACTURING comm- Y, or BRISTOL; CONNECTICUT, A COBPORATION or, CON

NECTIOUT' j-ABRADING MACHINE Application filedseptember28,1823. Serial No. 665,326.

, This invention relates to abrading Inachines and is herein shown as embodied in a machine for grinding balls; a One well known machine for grinding balls comprises a horizontal, circular ball holder or track, a pressure ringbearing on the balls 7 in the track' to'feed them around in the track and a rotary grinder b'earingfupwardly against the balls to reduce theni to size and 'sphericity. In such a machine, the circular track is filledby hand with balls-when the pressure ring is raised, the ring being lowered again for the grinding operation; Hith erto,.this stopping of the grinding operation and lifting of the ring to introduce the balls has been considered necessary becauseof the apparent impossibilityof otherwise gettingthe balls into the track between the 7 pressure ring andthe grinder. The capacity of the balltracklimits the quantity of balls that can be treated at one setting and it is necessary to raise the pressure ring and stop,

grinding whenever a ball is to be taken out and tested,.as for the purpose of showing" how far. the grinding has proceeded. -With such a machine, ball production is slow and intermittent, and separate operations ofthe machine for small batches of "balls, ground at different times, results in a lack-pf uniformity in the product. I p I I An objectof the invention, therefore, is to provide an improved ball grinding machine of this charactenwhich willoperate without constant interruption and increaseproduction with less attention on the part of the operator. Another object is to provide a grinder ofthis type whichwilloperate, at

one setting, on a large batch ofb'alls to secure uniformity. Still another object is to "provide such amachine with means for introducing balls during the grinding operation.

'To these. ends and also toimprove generally upon devices of'the character indicated my invention consists in the: variousmattershereinafter described and claimed.

Referring to QthedraWingS, Figure 1 is a front new of the apparatus, partly in ver- 1 ticjal section; 1

Fignre'g is'an iplan vie'w of a poretionof the-apparatus;.

tion;

Figure and Figure is a plan viewof the feed plate.

The numeral 10 indicates a circular support mounted on'a standard and 'carryinga. clamping ring :12, the lower edge of which is recessed to receive a ring 1 1, which,if desired, may be formed ina plurality ofsectionsbolted to the ring 12. Mounted cen: trally inside the ring is a normally fixed disc 16 which is recessedon'its under side atthe periphery to receive a substantially circular plate 18. Preferably the plate 18 is formed in segmental sections bolted to the disc. The opposing edges of the ring 14 and the cir- 41 is a front viewof the feed plate;

cular plate, 18 are bevelled or inclined, as at member 28 which is rotated on a vertical axis by a pulley 30 and the pressure member may be vertically adjusted to regulate the pressure by means of a hand-operated screw 32.

The pressure member bears with sufficient pressure on the balls to control their traverse forming-side lipsoverhanging theballs. The, pressure member is yieldably mounted on a and during this operation the grinding is eifected by an abrad-ing'member in thel'form;

of a'ring 34 which bears upwardly against the hallswhere theyproject below the guide and the ring is fixedto a disc 36 on a vertical shaft 38 drivenat highspeed by awpulley 10.-

' ltlshould be noted that the shaftBS ofthe abrading member is eccentrically {mounted with respect to theicenterof thefballtrack and the width of the abrading member and the eccentricity are such 1 that" the albra ding member wipes across the path of the balls and is thus worn evenly. This eccentric mounting also-leaves the balls exposed" on their under sides at a portion of their path 00 as will appear by referring to Figures 1 and 2. Here the continuity of the ball track or channel is interrupted, the ends of the channel coming at the sides of a gap in which a hardened feed plate 42 is fixed. The feed late hasa groove 44which is tangent to the all guide so that the transfer ofballs from the plate to the guide will occur without any resistance. A groove extension 46 extends at an obtuse angle to the groove 44, thus extending laterally beyond the edge of the pressure member and in this extension is laid the endof a flexible feed tube 48, the tube being cut away on its under side, to let the ballsv enter the groove and the tube being fastened by a clamp plate 50 secured by a screw 52 to the feed plate. Below the exposed portion of the bal guide at the gap in the latter'is an inclined chute 54 which conducts the balls downwardly from the delivery end of the track or channel around a 180 turn at 56 and into a series of buckets 58 having inclined bots toms 60. The buckets are supported on enclless chains passing over sprocket wheels and continuously driven in any suitable manner. As the balls are elevated in the buckets, they are discharged onto the reverse sides of the inclined bottoms 60 and directed into a hopper 62 mounted on a standard. The hopper may be of any suitable construction in which the balls are gathered and fed one by one into the feed tube 48 above mentioned.

As indicated in Figure 3 the bottom of the groove 44 lies below the level of the balls n the ball guide, this level being indicated by the brokenline 64. It is apparent that the pressure member 26 would interfere with any mere lateral introduction of the balls on a level with the ball guide, especially if a groove had been worn in the lower edge of the pressure member. The groove 44 is preferably inclined as shown and this inclination may be effected either by inclining the plate 42 or by making the entrance end of the groove 44 deeper than the end nearest the ball guide, as shown in Figure 4 at 44. lateral groove extension 46 allows the balls to pass freely under the pressure member and then the balls are forced up the incline by the' pressure of the stream of balls in the feed tube 48. As soon as the balls enter the ball guide they are fed around under trolof the pressure member.

With the above apparatus, it is not neces-; saryto raise the pressure member to take out a ball for testing purposes because azball may be readily picked out of the chute at anytime without interrupting the operation of .the

machine. Again, a large batch of balls can be treated at one setting, the capacity not being limited by the length of the ball guide but being increased by-the capacity of the chute, the buckets and the hopper. Thus all of the balls in a large batch are treated uni- The ber bearing on the upper portions of the balls to carry them around in the guide, a rotary abrading member arranged to engage the under portions of the balls and eccentrically mounted with respect to the ball guide to leave the balls exposed at a part of their path, a plate atthe exposed part of the path and having a ball'groove inclined upwardly towards the ball guide, and means for causing the balls to feed up saidinclined groove to the ball guide; substantially as described.

2. In a ball grinding machine, in combination, a horizontal annular ball guide constructed and arranged-to support the balls with their upper and lower portions projecting beyond the guide, a rotary pressure member bcaring on the upper portions of the balls to carry them around in the guide, a rotary abradingmember arranged to engage the under portions of the balls and eccentrically mounted with respect to the ball guide to leave the balls exposed at a part of their path,-a plate atthe exposed part of the path and having a ball groove inclined upwardly towards the ball guide, and an inclined tube connected to the groove, the pressure of a stream of balls in the tube forcing the balls up the inclined groove to'the guide; substantially as described.

3. In a ball grinding machine, in combination, a horizontal annular ball guide constructed and arranged to support the balls with their upper and lower portions projecting beyond the guide, a rotary pressure member bearing'on the upper portions of the balls to carry them around in the guide, a ro-' tary abrading member arranged to engage the under portions of the balls and eccentrically mounted with respect to the ball guide to leave the balls exposed at a part of their path, a plate interrupting the continuity of the-ball guide'and having a ball groove tangent to said ball guide, said groove supporting the balls below and out of contact with the pressure member; substantiallyas described.

4. In a ball grinding machine, in combination, a ball guide comprising a disc and a ring surrounding the disc and spaced therefrom to form a horizontal ball track, said guide allowing the balls to project above and below the disc and ring,- a pressure member bearing on the balls, a rotatable abrading the balls in the guide, and an inclined tube a 7 onto the guideinto contactwith the pressure bearing on the side. wallsand projecting member under the balls and eccentrically mounted with respect to the ball guide to leave the balls exposed on their underside at a portion of their path, a grooved plate set into the ring and having the bottom of its groove slightly below the lowest points of leading to the groove, the pressure of a stream of balls in the tube feeding the balls member substantially as described.

5. Ina ball grinding machine,-*in combination, a horizontal" annular ball guide comprising inner and outer fixed plates forming a channel with inclined side walls, the balls above and below the p1ates,\a rotary pressure member pressing the balls down against the fixed plates andcarrying them around in. the

7 channel, a rotary abrading member arranged to engage the under portions of the'balls and" eccentrically mounted with respect to the ball guide to leave the ball guide and the balls exposed at a part of their pathbeyond the periphery of the abrading member, and means for forcing a stream of balls under the pressure member and up into the ball guide at said exposed part of the path; substantially as described.

In testimony whereof I hereunto afiix my 7 signature. 7

WILLIAM PRATT. 

